RING 5Y0127 - Caterpillar

Personal injury or death can result from high voltage.When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present.Improper test equipment can fail and present a high voltage shock hazard to its user.Make sure the testing equipment is designed for and correctly operated for high voltage and current tests being made.When servicing or repairing electric power generation equipment:
Make sure the unit is off-line (disconnected from utility and/or other generators power service) , and either locked out or tagged DO NOT OPERATE.
Remove all fuses.
Make sure the generator engine is stopped.
Make sure all batteries are disconnected.
Make sure all capacitors are discharged.Failure to do so could result in personal injury or death. Make sure residual voltage in the rotor, stator and the generator is discharged.
When the engine-generator is operating, voltages up to 600V are present in these areas near or on the regulator:a. the regulator terminal stripb. the excitation transformer terminal strip (self-excited generator only)
Electronic components in the regulator can be damaged during generator operation if contact is made between the part and ground.
Remove the cover of the generator in order to clean the generator.Periodically, generators should be inspected for cleanliness. The following contaminants should not be allowed to accumulate on the windings:
dirt
dust
grease
salt
oil filmIf moisture is allowed to remain in contact with an electrical winding, some of the moisture will eventually be retained in voids or cracks of the insulation. This moisture will lower the resistance of the winding insulation. The insulation that is used on the windings of Caterpillar generators is moisture resistant. However, constant exposure to moisture will gradually lower the resistance of the insulation.Dirt can make the problem worse. Dirt can hold moisture in contact with the insulation. The salt that is present in sea air can compound the problem. When salt and moisture combine, a good electrical conductor is created. Clean the voltage regulator and clean the generator of dirt and debris. Use a brush to loosen accumulations of dirt. Vacuum clean the system in order to remove residual dirt. The use of compressed air is not recommended. Compressed air contains moisture that is present in the form of condensation.Carbon tracking on insulators can be caused by dirt or carbon tracking on insulators can be caused by loose connections. These carbon paths must be cleaned or the insulators must be replaced. A failure to correct a carbon tracking problem will result in an electrical short in the circuit.Visually check for loose wires or broken wires. Also, visually check for loose connections or broken connections. Check the wires and connections on the voltage regulator assembly. Check all wires and connections in the generator. Clean heat sinks. Make any necessary repairs to the wiring.Refer to Special Instruction, SEHS9124, "Cleaning and Drying of the Generator" for more information.